Association of increased parathyroid hormone with neuroendocrine activation and endothelial dysfunction in elderly men with heart failure

Endocrine hormone imbalance in heart failure with reduced ejection fraction: A cross-sectional study

Background and Aims

Sustained neurohormonal activation plays a central role in the progression of heart failure (HF). Other endocrine axes may also be affected. It was the aim of this study to examine the endocrine profile (thyroid, parathyroid, glucocorticoid, and sex hormones) in a contemporary sample of patients with HF and reduced ejection fraction (EF) on established disease-modifying therapy.

Methods

This study prospectively measured morning fasting hormones in 52 ambulatory and stable HF patients with EF < 50% on disease-modifying therapy (mean age 63 ± 11 years, 29% female, mean LVEF 32 ± 9.6%) and compared them to 54 patients at elevated risk for HF (61 ± 12 years, 28% female) and 62 healthy controls (HC; 61 ± 13 years, 27% female). Main comparisons were performed using one-way analysis of variance. Associations with biomarkers were studied with linear regression.

Results

HF patients showed a reduced free triiodothyronine (fT3)/free thyroxine (fT4) ratio compared to HC (0.30 ± 0.06 vs. 0.33 ± 0.05, p = 0.046). Parathyroid hormone (PTH) and cortisol were increased in HF compared to both HC (median [IQR] 59 [50-84] vs. 46 [37-52] ng/L, p < 0.001 and 497 ± 150 vs. 436 ± 108 nmol/L, p = 0.03, respectively) and patients at risk (both p < 0.001). Total testosterone was reduced in male HF compared to HC (14.4 ± 6.6 vs. 18.6 ± 5.3 nmol/L; p = 0.01). No differences in TSH, estradiol, progesterone, and prolactin were found. Lower fT3 levels were found in HF with EF < 40% versus EF 40%-49% (4.6 ± 0.3 vs. 5.2 ± 0.7 pmol/L, p = 0.009). In HF patients, fT3 was an independent predictor of NT-proBNP and high-sensitivity troponin T in multiple regression analysis. PTH was positively associated with NT-proBNP.

Conclusion

There is evidence of endocrine hormonal imbalance in HF with reduced EF beyond principal neurohormones and despite the use of disease-modifying therapy.

Plasma Levels of Intact Parathyroid Hormone and Congestion Burden in Heart Failure: Clinical Correlations and Prognostic Role

Circulating parathyroid hormone (PTH) concentrations increase in heart failure (HF) and are related to disease severity. The relationship between PTH and congestion is still a matter of debate. The objective of this analysis was to evaluate the role of PTH as a marker of congestion and prognosis in HF. We enrolled 228 patients with HF. Intact PTH concentrations and HYDRA score (constituted by: B-type natriuretic peptide, blood urea nitrogen−creatinine ratio, estimated plasma volume status, and hydration status) were evaluated. The study endpoint was all-cause mortality. PTH levels were higher in acute compared with chronic HF and in patients with clinical signs of congestion (i.e., peripheral oedema and orthopnea). PTH concentrations significantly correlated with NYHA class and HYDRA score. At multivariate analysis of HYDRA score, estimated glomerular filtration rate (eGFR), and corrected serum calcium were independently determinants of PTH variability. Fifty patients (22%) died after a median follow-up of 408 days (interquartile range: 283−573). Using univariate Cox regression analysis, PTH concentrations were associated with mortality (hazard ratio [HR]: 1.003, optimal cut-off: >249 pg/mL—area under-the-curve = 0.64). Using multivariate Cox regression analysis, PTH was no longer associated with death, whereas HYDRA score, left ventricular ejection fraction, and eGFR acted as independent predictors for mortality (HR: 1.96, 0.97, and 0.98, respectively). Our study demonstrated that intact PTH was related to clinical and subclinical markers of congestion. However, intact PTH did not act as an independent determinant of all-cause death in HF patients.

Sex-Specific Relationship Between Parathyroid Hormone and Platelet Indices in Phenotypes of Heart Failure-Results From the MyoVasc Study

Background: Heart failure (HF) is a multifactorial syndrome with pathophysiological complexities still not fully understood. Higher mean platelet volume (MPV), a potential marker of platelet activation, and high concentrations of parathyroid hormone (PTH) have been implicated in the pathogenesis of HF.

Aim: This study aims to investigate sex-specifically the association between PTH concentrations and platelet indices in phenotypes of HF.

Methods and Results: PTH and platelet indices (MPV and platelet count) were available in 1,896 participants from the MyoVasc study in Mainz, Germany. Multivariable linear regression models, adjusted for age, sex, season, vitamin D status, cardiovascular risk factors, comorbidities, estimated glomerular filtration rate, and medication, were used to assess the associations between platelet indices and PTH. The results showed distinct sex-specific associations between PTH and platelet indices. A positive association between PTH and MPV was found in females with symptomatic HF with reduced ejection fraction (HFrEF) only [β = 0.60 (0.19; 1.00)]. Platelet count was inversely associated with PTH in male HFrEF individuals [β = −7.6 (−15; −0.30)] and in both males and females with HF with preserved ejection fraction (HFpEF).

Conclusion: This study reports differential, sex-specific relationships between PTH and platelet indices in HF individuals independent of vitamin D status and clinical profile. Particularly in phenotypes of symptomatic HF, distinct associations were observed, suggesting a sex-specific mechanism involved in the interaction between PTH and platelets.

Evaluation of Vitamin D Levels and Response to Therapy of Childhood Migraine

Background and Objectives: Vitamin D deficiency and insufficiency are related with many neurological diseases such as migraine. The aim of this study was to investigate whether pediatric migraine is associated with vitamin D deficiency and the effect of vitamin D therapy on the frequency, duration, severity of migraine attacks, and Pediatric Migraine Disability Assessment (PedMIDAS). Materials and Methods: We retrospectively examined the patients’ levels of calcium, phosphorus, parathyroid hormone, alkaline phosphatase, and 25-OH vitamin D of 92 pediatric migraine patients. The patients were divided into two groups: Group 1, which had low vitamin D levels and received vitamin D therapy, and group 2, which had normal vitamin D levels and did not receive vitamin D therapy. Migraine severity measured by the visual analog scale (VAS), migraine frequency, and duration as well as scores on the PedMIDAS questionnaire were compared with regard to the 25-OH vitamin D levels. In addition, pre- and posttreatment pedMIDAS scores, VAS, migraine frequency, and duration were compared with baseline values. Results: A total of 34.7% patients had vitamin D insufficiency (vitamin D levels between 10 and 20 ng/mL), whereas 10.8% had vitamin D deficiency (vitamin D levels < 10 ng/mL). Migraine frequency, migraine duration, and PedMIDAS scores were significantly higher in the group 1 than group 2 (p = 0.004, p = 0.008, and p = 0.001). After vitamin D therapy at sixth months of supplementation, migraine duration was reported statistically significant shorter (p < 0.001) and the migraine frequency, VAS scores, and pedMIDAS scores were statistically significant lower compared with baseline values in group 1 (p < 0.001). Conclusion: We found a marked correlation between pediatric migraine and vitamin D levels. Vitamin D therapy was beneficial in migraine pediatric patients.

Relationship of High Circulating Cystatin C to Biochemical Markers of Bone Turnover and Bone Mineral Density in Elderly Males with a Chronic Heart Failure

Background

The aim of the study was to investigate the association of Cystatin C (CysC) to biochemical markers of bone turnover and bone mass, and to evaluate its prognostic significance in elderly males with chronic heart failure (CHF).

Methods

A prospective cohort study was executed on sixtyeight males (mean age 68±7 years) with mild to moderate CHF, together with 19 of corresponding age- and body mass index-matched healthy individuals who underwent cardio vascular, bone mineral density (BMD), and body com position assessment. Biochemical assessment of all subjects included NT-pro-BNP, parathyroid hormone (PTH), 25-hydroxy vitamin D (25(OH)D), CysC, and biochemical markers of bone turnover including osteocalcin (OC), alkaline phosphatase (ALP), β-CrossLaps (β-CTx), osteoprotegerin (OPG), and receptor activator of nuclear factor κB ligand (RANKL).

Results

Serum CysC was significantly increased in males with CHF in comparison to healthy control ones. A significant positive association was found between CysC levels and OC in males with CHF, while OC and β-CTx increased in increasing CysC tertiles. In multivariate regression analysis, OC and smoking were a significant determinant of CysC in males with CHF. Level of CysC was found to be positively associated with an increased fatal risk in males with CHF.

Conclusions

Serum osteocalcin is an independent predictor of CysC level in elderly males with CHF. Higher CysC level showed a negative relation to survival and bone loss in males with CHF. Further research is needed to confirm the potential role of CysC in the crosstalk between heart, kidney, bone, and energy metabolism in CHF.

Parathyroid Hormone Causes Endothelial Dysfunction by Inducing Mitochondrial ROS and Specific Oxidative Signal Transduction Modifications

Vitamin D deficiency contributes to cardiovascular risk (CVR), with hyperparathyroidism advocated as a putative mechanism. Indeed, mounting evidence supports the hypothesis that parathyroid hormone (PTH) impairs endothelial function, even though mechanisms are not fully elucidated. The present study was designed to verify in vitro the ability of sustained exposure to PTH to cause endothelial dysfunction, exploring the underlying mechanisms. In bovine aortic endothelial cells (BAECs), we evaluated the effects of PTH exposure (0.1 nM–24 hours) on both endothelial response to vasodilators, such as bradykinin (Bk (30 nM)) and acetylcholine (Ach (1 μM)), and angiogenic competence. Pretreatment with PTH impaired endothelial response to Bk but not to Ach, in terms of cytosolic calcium fluxes and NO production. In order to explore the underlying mechanisms, we assessed the production of total and mitochondrial ROS (tROS and mROS, respectively) in response to PTH (at 1 and 3 hours). PTH increased ROS generation, to an extent high enough to determine oxidation of Bk receptor B2. Conversely, the oxidation levels of M1 and M3 Ach receptors were not affected by PTH. A mROS selective scavenger (MitoTEMPO (5 μM)) restored the endothelial responsiveness to Bk while the well-known antioxidant properties of vitamin D (100 nM) failed to counteract PTH-mediated oxidative stress. PTH determined mitochondrial calcium fluxes ([Ca²⁺]_mt) and the mitochondrial calcium uniporter inhibitor Ru360 (10 μM) reduced mROS production and prevented the PTH-mediated endothelial dysfunction. Angiogenic competence was evaluated as tubular formations in the endothelial Matrigel assay and showed a significant impairment in PTH-pretreated cells (0.1 nM–24 hours), despite the increase in VEGF transcriptional levels. VEGFR2 oxidation occurred in response to PTH, suggesting that even the impairment of angiogenesis was due to the ROS surge. These results indicate that PTH affects endothelial function through ROS production, driven by mitochondrial calcium overload. PTH-induced oxidative stress might act as signaling modifiers, altering specific pathways (Bk and VEGF) and preserving others (Ach).

The Role of Parathyroid Hormone and Vitamin D Serum Concentrations in Patients with Cardiovascular Diseases

25-hydroxyvitamin D (25(OH)D) plays a crucial role in human homeostasis. Its deficiency (vitamin D deficiency—VDD), being common in European population, combined with elevated concentration of parathyroid hormone (PTH), represents a vicious cycle of mechanisms leading to heart failure (HF). Despite several papers published in that field, the effect of VDD and PTH concentration on cardiovascular system remains unequivocal; thus, the aim of the study was to compare these data among HF and non-HF patients being prospectively enrolled into the study during hospital stay in the cardiology ward. Patients with HF had higher PTH concentration (85.0 ± 52.6 versus 64.5 ± 31.7, p ≤ 0.02) compared to non-HF patients. Mean PTH values were associated with the clinical status expressed by the New York Heart Association class (NYHA class) (“0”—66.04, “I”—56.57, “II”—72.30, “III”—85.59, and “IV”—144.37 pg/ml, p ≤ 0.00004). Interestingly, neither 25(OH)D (31.5 versus 29.7 ng/ml, p ≤ ns) nor phosphorus (P) (1.23 versus 1.18 mmol/l, p ≤ ns) nor total calcium (Ca²⁺) concentration (2.33 versus 2.37 mmol/l, p ≤ ns) differed among the groups. Reassuming PTH serum concentration in contrary to 25(OH)D, P and Ca²⁺ are significantly raised among the patients with HF and shows significant relationship with the clinical status expressed by the NYHA class.

Parathyroid hormone promotes osteoblastic differentiation of endothelial cells via the extracellular signal-regulated protein kinase 1/2 and nuclear factor-κB signaling pathways

Vascular calcification (VC) occurs in patients with chronic kidney disease (CKD) and contributes to cardiovascular dysfunction and mortality. Parathyroid hormone (PTH) is a crucial regulator of VC. High PTH serum levels constitute as a major risk factor for patients with CKD. However, the effect and mechanism of PTH on osteoblastic differentiation in endothelial cells have not been fully elucidated. In the present study, the role of PTH in VC was investigated using an in vitro calcification model. Endothelial cells were stimulated with PTH in the femto- to picomolar range. As determined by western blot analysis and ELISA, osteoblastic differentiation, as indicated by the BMP2 marker, occurred with maximum effect at 1×10^-10 mmol/l PTH. The results indicate that PTH promotes osteoblastic differentiation of endothelial cells, as demonstrated by the increased expression of bone morphogenetic protein (BMP) 2 and BMP4. In addition, western blot analysis revealed that PTH activated the extracellular signal-regulated protein kinase (Erk)1/2 and nuclear factor (NF)-κB signaling pathways. However, reverse transcription-quantitative polymerase chain reaction demonstrated that inhibitors specific to Erk1/2 and NF-κB eradicated the effect of PTH treatment on BMP2, BMP4, ALP and RUNX2 expression. These results demonstrate that PTH promotes the osteoblastic differentiation of endothelial cells via the Erk1/2 and NF-κB signaling pathways, which suggests a potential role of PTH in the promotion of VC. These findings provide an insight into the association between PTH and cardiovascular disease.

Secondary hyperparathyroidism prevalence and prognostic role in elderly males with heart failure

AIM

Evaluation of secondary hyperparathyroidism (SHPT) and its prognostic impact on all-cause mortality in elderly males with heart failure (HF).

METHODS

Seventy three males (67 ± 7 years old) with systolic HF were included. Baseline PTH was measured. Patients were grouped according to PTH cut-off levels of 65 pg/ml (>65 pg/ml = SHPT vs. normal PTH). All-cause mortality was evaluated at 6-year follow-up.

RESULTS

SHPT was diagnosed in 43 (59 %) patients. They were more severe compared to the patients with normal PTH regarding NYHA functional class (2.4 ± 0.5 vs. 2.1 ± 0.2, p = 0.001), quality of life score (34 ± 14 vs. 24 ± 12, p = 0.005), 6-min walking distance (378 ± 79 vs. 446 ± 73 m, p < 0.0001), left ventricular ejection fraction (27 ± 8 vs. 31 ± 7 %, p = 0.019), and NT-proBNP [2452 (3399) vs. 918 (1372) pg/ml, p < 0.0001]. No differences in age, vitamin D status, and renal function were noted between studied groups. A total of 41 (56 %) patients died within 6 years of follow-up. Kaplan-Meier survival analysis showed impaired long-term survival in patients with SHPT versus patients with normal PTH (p = 0.009). The rate of death was highest (75 %) in the group of patients with SHPT and NT-proBNP levels above median value (p = 0.003). Cox regression analysis demonstrated that NT-proBNP was the single independent predictor of all-cause mortality at 6-year follow-up [HR 3.698 (1.927-7.095), p < 0.0001].

CONCLUSION

SHPT was highly prevalent in elderly males with HF and was associated with impaired survival. HF patients with SHPT had more severe disease compared to the patients with normal serum PTH. Determination of serum PTH levels provided additional value to NT-proBNP for risk stratification in these patients.

Circulating Fibroblast Growth Factor 23 Has a U-Shaped Association With Atrial Fibrillation Prevalence

BACKGROUND

Atrial fibrillation (AF) occurs more frequently among patients with renal dysfunction. We investigated the possible association between prevalence of AF and serum fibroblast growth factor 23 (FGF23), which has been shown to be increased in subjects with renal dysfunction.

METHODS AND RESULTS

Among the total enrollment of 851 cardiac patients, 188 patients had AF (paroxysmal AF, 95; non-paroxysmal AF, 93). Prevalence of AF for FGF23 octile had a U-shaped relationship with the lowest prevalence at the fifth octile. On logistic regression analysis, when the third FGF23 quartile was used as the reference, the first and fourth FGF23 quartiles were associated with prevalence of AF with an odds ratio (OR) of 3.34 (95% confidence interval [CI]: 1.89-5.88) and 2.58 (95% CI: 1.45-4.58), respectively, after adjusting for confounding factors including estimated glomerular filtration rate (eGFR). Among the subgroup of 416 patients for whom serum parathyroid hormone and 25-hydroxy vitamin D data were available, OR of the first and the fourth FGF23 quartile were calculated to be 3.52 and 2.97, respectively, when further adjusted for these two variables in the statistical model.

CONCLUSIONS

Serum FGF23 had a U-shaped relationship with prevalence of AF among Japanese cardiac patients, which was independent of other calcium/phosphate metabolism-related parameters and eGFR. Pathophysiology underlying the observed link, if at all, awaits further investigation.

Liver function parameters in hip fracture patients: relations to age, adipokines, comorbidities and outcomes

AIM

To asses liver markers in older patients with hip fracture (HF) in relation to age, comorbidities, metabolic characteristics and short-term outcomes.

METHODS

In 294 patients with HF (mean age 82.0±7.9 years, 72.1% women) serum alanine aminotransferase (ALT), gammaglutamyltransferase (GGT), alkaline phosphatase (ALP), albumin, bilirubin, 25(OH)vitaminD, PTH, calcium, phosphate, magnesium, adiponectin, leptin, resistin, thyroid function and cardiac troponin I were measured.

RESULTS

Elevated ALT, GGT, ALP or bilirubin levels on admission were observed in 1.7%-9.9% of patients. With age GGT, ALT and leptin decrease, while PTH and adiponectin concentrations increase. Higher GGT (>30 U/L, median level) was associated with coronary artery disease (CAD), diabetes mellitus (DM), and alcohol overuse; lower ALT (≤20 U/L, median level) with dementia; total bilirubin>20 μmol/L with CAD and alcohol overuse; and albumin>33 g/L with CAD. Multivariate adjusted regression analyses revealed ALT, ALP, adiponectin, alcohol overuse and DM as independent and significant determinants of GGT (as continuous or categorical variable); GGT for each other liver marker; and PTH for adiponectin. The risk of prolonged hospital stay (>20 days) was about two times higher in patients with GGT>30 U/L or adiponectin>17.14 ng/L (median level) and 4.7 times higher if both conditions coexisted. The risk of in-hospital death was 3 times higher if albumin was <33 g/L.

CONCLUSIONS

In older HF patients liver markers even within the normal range are associated with age-related disorders and outcomes. Adiponectin (but not 25(OH)vitaminD, PTH, leptin or resistin) is an independent contributor to higher GGT. Serum GGT and albumin predict prolonged hospital stay and in-hospital death, respectively. A unifying hypothesis of the findings presented.

Serum parathyroid hormone as a potential novel biomarker of coronary heart disease

OBJECTIVE

This study aimed to evaluate the relationships between serum parathyroid hormone (PTH) and coronary heart disease (CHD).

METHODS

From July 2011 to February 2013, a total of 79 CHD patients and 94 normal control patients with ages ranging from 25 to 79 years were included in this study. Serum PTH level and common risk factors of CHD (age, gender, cholesterol, glycosylated hemoglobin [HbA1c], blood pressure [BP], history of diabetes, smoking, and body mass index) were investigated. Pearson's correlation and multiple regression analyses were used to evaluate the relationships between serum PTH level and CHD risk factors. All statistical analyses were performed using the SPSS 18.0 software.

RESULTS

RESULTS from Pearson's correlation analysis indicated that age, systolic blood pressure (SBP), diastolic blood pressure (DBP), low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol (HDL-c), HbA1c, history of smoking, and serum PTH level were risk factors for CHD (all p<0.05). Serum PTH levels were positively correlated with DBP (r=0.256, p=0.010) and HbA1c (r=0.223, p=0.003), while not being related to other risk factors of CHD (all p>0.05). Multiple linear regression analysis showed that SBP, DBP, LDL-c, and HDL-c may be important determinants of CHD (all p<0.05). Further, serum PTH level is also an independent risk factor for CHD (p<0.001).

CONCLUSION

Our results provide evidence that serum PTH level may be involved in the pathogenesis of CHD. Thus, PTH could be used as an important biomarker in the diagnosis of CHD.

Interplay of parathyroid hormone and aldosterone antagonist in prevention of heart failure hospitalizations in chronic kidney disease

BACKGROUND

Aldosterone antagonists may mediate their effects on heart failure through parathyroid hormone (PTH) in chronic kidney disease (CKD) patients.

METHODS

Patients with CKD on spironolactone were selected and matched for age, gender, race, use of a vitamin D analogue, the number of antihypertensive medications, and CKD stage. PTH levels before and after the first prescription of spironolactone were measured. A thorough chart review was conducted to assess for heart failure hospitalizations. An adjusted Cox proportional model was used to calculate the hazard ratio (HR) for heart failure hospitalizations among cases versus controls.

RESULTS

There were a total of 950 (mean age 67±13 years, 40% men) patients with CKD. Of these, there were 48 hospitalizations for heart failure among the cases and 82 among the controls (HR 0.37; 95% confidence interval (CI) 0.19-0.74, p=0.005). We noted a more significant decrease in PTH levels among the cases when compared to the controls (p<0.0001). The adjusted hazard for heart failure hospitalization increased with higher PTH levels (p=0.002) and mediation analysis revealed change in PTH level as a significant mediator of heart failure hospitalization (p=0.04).

CONCLUSION

Aldosterone antagonists may be helpful in preventing hospitalizations for heart failure exacerbation in CKD patients through a PTH-mediated effect.

PTH: Potential role in management of heart failure

Biomarkers play an important role for the diagnosis and prognosis of heart failure (HF), a disease with high morbidity and mortality as well as a huge impact on healthcare budgets. Parathyroid hormone (PTH) is a major systemic calcium-regulating hormone and an important regulator of bone and mineral homeostasis. PTH testing is important for differential diagnosis of calcemia related disorders and for the management of patients with chronic kidney disease. As secondary hyperparathyroidism has been evidenced in HF patients, PTH testing might be relevant in HF patients for risk stratification and more personalized selection of treatment.

Can parathyroid hormone be used as a biomarker for heart failure?

Secondary hyperparathyroidism in heart failure is a consequence of renin-angiotensin-aldosterone activation, chronic hyperaldosteronism, and loop diuretic usage, resulting in calcium excretion. The result is an inflammatory state with adverse effects on myocardial remodeling and systemic complications. Recent literature has suggested that elevated parathyroid hormone predicts adverse outcomes in patients with heart failure independent of serum calcium and phosphate, vitamin D deficiency, and renal insufficiency. Parathyroid hormone has been correlated with elevated brain natriuretic peptide levels, an established biomarker of heart failure severity. There are several limitations to the utilization of parathyroid hormone as a biomarker for heart failure, and further prospective studies need to be conducted to assess the value of multiple parathyroid hormone measurements over time and elucidate the role of parathyroid hormone in diastolic dysfunction. Pending further validation, there is promise for parathyroid hormone as a complementary biomarker in heart failure.

Vitamin D status in migraine patients: a case-control study

Background. There have been few studies on the relation between vitamin D and migraine. We investigated the prevalence of vitamin D deficiency in migraine patients and compared it with a control group. We also evaluated the relationship of vitamin D deficiency with severity of migraine. Methods. 105 newly diagnosed migraine patients and 110 controls, matched for age, sex, socioeconomic status, education, and sun exposure, were enrolled during the spring of 2011. 25-Hydroxy vitamin D [25(OH)D] plasma levels were measured by chemiluminescence immunoassay. Results. The mean ± SE concentration of 25(OH)D was 13.55 ± 0.91 ng/mL in cases and 13.19 ± 1.19 ng/mL in controls. There was no significant difference in 25(OH)D concentration between cases and controls. We found no relationship between severity of headache and 25(OH)D status. Conclusions. We did not find any association between migraine and vitamin D status; also, severity of headaches was not related to 25(OH)D level. Further studies with larger sample sizes are required to confirm our results.

Cinacalcet attenuates the renal endothelial-to-mesenchymal transition in rats with adenine-induced renal failure

Elevated serum parathyroid hormone (PTH) is an important complicated phenomenon in patients with chronic kidney disease (CKD). Emerging evidence indicates the involvement of PTH in organ fibrosis, and suppression of PTH by cinacalcet (CINA) ameliorates the progression of fibrotic disorders. However, the underlying mechanisms are largely unknown. The endothelial-to-mesenchymal transition (EndMT) has been shown to be an important mechanism involved in renal fibrosis. The present study aimed to investigate whether CINA treatment attenuated renal EndMT in rats with adenine-induced chronic renal failure (CRF). Compared with the control group, serum PTH was significantly higher in the CRF group and was suppressed after CINA treatment. Serum calcium, phosphorus, and calcium × phosphorus product levels were similar in the CRF group and CINA-treated CRF group. Renal collagen accumulation was significantly increased in the CRF group, which was markedly ameliorated by CINA treatment. Expression of the endothelial marker CD31 was significantly downregulated in rats with CRF, whereas expression of the mesenchymal markers fibroblast specific-protein 1 and α-smooth muscle actin was markedly upregulated. These changes were inhibited by CINA treatment. The protein levels of these EndMT-related markers were strongly correlated with serum PTH concentrations. Furthermore, the in vitro study showed that PTH could significantly increase the expression of fibroblast specific-protein 1 and α-smooth muscle actin and decrease CD31 in mRNA and protein levels in a concentration- and time-dependent manner. In conclusion, our study suggests that reducing serum PTH by CINA treatment could attenuate renal fibrosis via suppression of EndMT in the adenine-induced CRF rat model.

Parathyroid hormone, vitamin D levels and urine albumin excretion in older persons: the 2011 Korea National Health and Nutrition Examination Survey (KNHANES)

OBJECTIVE

Persistent elevation of urinary albumin excretion (UAE), even within normal range, is an independent predictor for cardiovascular disease. Accumulating research suggests that low levels of vitamin D and high levels of parathyroid hormone (PTH) also increase cardiovascular disease risk. This study is intended to investigate the relationship between PTH, vitamin D levels and UAE.

METHODS

We examined 2897 adults aged 50 and above, participating in the second year of the fifth Korea National Health and Nutrition Examination Survey (KNHANES V-2). Anthropometric and laboratory measurements were performed. Elevated UAE was defined as spot urinary albumin creatinine ratio equal or above 10.

RESULTS

The proportion of elevated UAE (21·8%, 23·2%, 23·2%, 31·8%; P for trend = 0·002) rose with increasing quartiles of PTH. The odds ratio for elevated UAE in the highest quartile of PTH was 72% higher than the lowest quartile group. There was no relationship between vitamin D and elevated UAE.

CONCLUSIONS

Elevated PTH levels are associated with elevated UAE in Korean adults aged 50 and above. Additional studies are needed to clarify this relationship.

Cardiovascular diseases in older patients with osteoporotic hip fracture: prevalence, disturbances in mineral and bone metabolism, and bidirectional links

BACKGROUND

Considerable controversy exists regarding the contribution of mineral/bone metabolism abnormalities to the association between cardiovascular diseases (CVDs) and osteoporotic fractures.

AIMS AND METHODS

To determine the relationships between mineral/bone metabolism biomarkers and CVD in 746 older patients with hip fracture, clinical data were recorded and serum concentrations of parathyroid hormone (PTH), 25-hydroxyvitamin D, calcium, phosphate, magnesium, troponin I, parameters of bone turnover, and renal, liver, and thyroid functions were measured.

RESULTS

CVDs were diagnosed in 472 (63.3%) patients. Vitamin D deficiency was similarly prevalent in patients with (78.0%) and without (82.1%) CVD. The CVD group had significantly higher mean PTH concentrations (7.6 vs 6.0 pmol/L, P < 0.001), a higher prevalence of secondary hyperparathyroidism (SPTH) (PTH > 6.8 pmol/L, 43.0% vs 23.3%, P < 0.001), and excess bone resorption (urinary deoxypyridinoline corrected by creatinine [DPD/Cr] > 7.5 nmol/μmol, 87.9% vs 74.8%, P < 0.001). In multivariate regression analysis, SHPT (odds ratio [OR] 2.6, P = 0.007) and high DPD/Cr (OR 2.8, P = 0.016) were independent indictors of CVD. Compared to those with both PTH and DPD/Cr in the normal range, multivariate-adjusted ORs for the presence of CVD were 17.3 (P = 0.004) in subjects with SHPT and 9.7 (P < 0.001) in patients with high DPD/Cr. CVD was an independent predicator of SHPT (OR 2.8, P = 0.007) and excess DPD/Cr (OR 2.5, P = 0.031). CVD was predictive of postoperative myocardial injury, while SHPT was also an independent predictor of prolonged hospital stay and in-hospital death.

CONCLUSION

SHPT and excess bone resorption are independent pathophysiological mediators underlying the bidirectional associations between CVD and hip fracture, and therefore are important diagnostic and therapeutic targets.

Endothelial function in mild primary hyperparathyroidism

BACKGROUND

It is not known if endothelial dysfunction, an important early event in the pathogenesis of atherosclerosis, is present in mild primary hyperparathyroidism (PHPT) and if so, whether it improves following parathyroidectomy.

DESIGN

We measured flow-mediated vasodilation (FMD), which estimates endothelial function by ultrasound imaging, in patients prior to and 6 and 12 months after parathyroidectomy.

RESULTS

Forty-five patients with mild PHPT [80% female, 61 ± 1 (mean ± SE) years, serum calcium 2·65 ± 0·03 mm (10·6 ± 0·1 mg/dl), PTH 10·5 ± 0·7 pm (99 ± 7 pg/ml), 25-hydroxyvitamin D (25OHD) 70·3 ± 3·7 nm (28·2 ± 1·5 ng/ml)] were studied. Baseline FMD was normal (4·63 ± 0·51%; reference mean: 4·4 ± 0·1%) and was not associated with serum calcium, PTH or 25OHD levels. In the group as a whole, FMD did not change after surgery (6 months: 4·38 ± 0·83%, P = 0·72; 12 months: 5·07 ± 0·74%, P = 0·49). However, in those with abnormal baseline FMD (<2·2%; n = 15), FMD increased by 350%, normalizing by 6 months after surgery (baseline: 0·81± 0·19%; 6 months: 3·18 ± 0·79%, P = 0·02 vs baseline; 12months: 3·68 ± 1·22%, P = 0·04 vs baseline). Baseline calcium, PTH and 25OHD levels did not differ between those with abnormal vs normal FMD, nor did these indices predict postoperative change in FMD.

CONCLUSIONS

FMD is generally normal in patients with mild PHPT and is unchanged 1 year after parathyroidectomy. Although FMD may normalize after surgery in patients with baseline abnormalities, data do not support using endothelial dysfunction as an indicator for parathyroidectomy.

Heart failure as a risk factor for osteoporosis and fractures

Although heart failure (HF) and osteoporosis are common diseases, particularly in elderly populations, patients with HF have an increased risk for osteoporosis. The relationship of HF with osteoporosis is modified by gender and the severity of HF. In addition, shared risk factors, medication use, and common pathogenic mechanisms affect both HF and osteoporosis. Shared risk factors for these 2 conditions include advanced age, hypovitaminosis D, renal disease, and diabetes mellitus. Medications used to treat HF, including spironolactone, thiazide diuretics, nitric oxide donors, and aspirin, may protect against osteoporosis. In contrast, loop diuretics may make osteoporosis worse. HF and osteoporosis appear to share common pathogenic mechanisms, including activation of the renin-angiotensin-aldosterone system, increased parathyroid hormone levels, and/or oxidative/nitrosative stress. HF is a major risk factor for mortality following fractures. Thus, in HF patients, it is important to carefully assess osteoporosis and take measures to reduce the risk of osteoporotic fractures.

Increased circulating concentrations of bioactive PTH 1-84 in patients with heart failure

BACKGROUND

PTH is related to left ventricular hypertrophy and its circulating levels are associated with worse prognosis in patients with heart failure (HF). The objectives of our study were to measure the circulating levels of bioactive PTH 1-84 through third-generation assay in HF patients, to determine their association with the disease severity as well as their relation with recognized biomarkers of HF worsening and prognosis.

METHODS

PTH 1-84 concentrations were determined in 76 HF patients and in 49 healthy volunteers. Circulating levels of amino-terminal proatrial natriuretic peptide (Nt-proANP), B-type natriuretic peptide (BNP), Nt-proBNP, proBNP, and big endothelin-1 (Big ET-1) were also measured.

RESULTS

HF patients had in- creased PTH 1-84 levels in comparison to controls. A significant increase of the PTH 1-84 circulating concentrations was observed according to the New York Heart Association functional classes. PTH 1-84 circulating concentrations were also significantly correlated with Nt-proANP, BNP, Nt-proBNP, proBNP, and Big ET-1.

CONCLUSIONS

PTH 1-84 circulating levels are significantly increased in HF patients in comparison to healthy individuals. Our study has also demonstrated that circulating concentrations of bioactive PTH are related to HF severity and well-established biomarkers of the worsening of the disease.

C-terminal FGF23 is a strong predictor of survival in systolic heart failure

Fibroblast growth factor 23 (FGF23) is a bone-derived hormone involved in the regulation of phosphate and calcium metabolism. We have evaluated the levels of C-terminal FGF23 (Ct-FGF23) in 73 patients presenting heart failure with reduced ejection fraction (HF-REF) and assess their potential predictive value for long-term survival through a 6 years follow-up. Ct-FGF23 levels were markedly increased in HF-REF. In univariate proportional hazard model, survival was related to glomerular filtration rate (eGFR), intact parathyroid hormone (PTH), B-type natriuretic peptides (BNP) and Ct-FGF23. In a multivariate analysis including age, EF, PTH, BNP, Ct-FGF23, calcium, phosphorus and eGFR levels, Ct-FGF23 is the strongest predictor of long term CV death.

Parathyroid hormone response to vitamin D insufficiency in elderly males with chronic heart failure

Secondary hyperparathyroidism (SHPT) may contribute to the systemic illness that accompanies chronic heart failure (CHF). Healthy elderly with vitamin D deficiency who did not develop hyperparathyroidism (functional hypoparathyroidism, FHPT) had lower mortality than those who did. This study was designed to examine determinants of the PTH response in the vitamin D insufficient CHF patients. Sixty five vitamin D insufficient males with NYHA class II and III and 20 control subjects age >/=55 years were recruited. Echocardiography, physical performance, NT-pro-BNP, PTH, 25-hydroxyvitamin D (25(OH)D), adiponectin and bone activity surrogate markers (OPG, RANKL, OC, beta-CTx) were assessed. Increased NYHA class was associated with SHPT, while physical performance was inferior compared to FHPT. SHPT was associated with lower left ventricular ejection fraction (LVEF) and flow mediated dilatation, but with higher left heart dimensions, left ventricular mass index and right ventricular systolic pressure. CHF patients with SHPT had increased NT-pro-BNP, adiponectin and bone markers, but decreased 25(OH)D compared to those with FHPT. Independent determinants for SHPT in CHF patients with vitamin D insufficiency were LVEF, adiponectin and beta-CTx, irrespective of renal function and serum vitamin D levels. In conclusion, increased PTH levels, but not low vitamin D, demonstrated close relation to CHF severity.

Functional proteomic analysis reveals sex-dependent differences in structural and energy-producing myocardial proteins in rat model of alcoholic cardiomyopathy

Long-term ethanol exposure leads to a sexually dimorphic response in both the susceptibility to cardiac pathology (protective effect of the female heart) and the expression of selected myocardial proteins. The purpose of the present study was to use proteomics to examine the effect of chronic alcohol consumption on a broader array of cardiac proteins and how these were affected between the sexes. Male and female rats were maintained for 18 wk on a 40% ethanol-containing diet in which alcohol was provided in drinking water and agar blocks. Differences in the content of specific cardiac proteins in isopycnic centrifugal fractions were determined using mass spectrometry on iTRAQ-labeled tryptic fragments. A random effects model of meta-analysis was developed to combine the results from multiple iTRAQ experiments. Analysis of a network of proteins involved in cardiovascular system development and function showed that troponins were oppositely regulated by alcohol exposure in females (upregulated) vs. males (downregulated), and this effect was validated by Western blot analysis. Pathway analysis also revealed that alcohol-consuming males showed increased expression of proteins involved in various steps of oxidative phosphorylation including complexes I, III, IV, and V, whereas females showed no change or decreased content. One implication from these findings is that females may be protected from the toxic effects of alcohol due to their ability to maintain contractile function, maintain efficiency of force generation, and minimize oxidative stress. However, the alcohol-induced insult may lead to increased production of reactive oxygen species and structural abnormalities in male myocardium.